Core 1 will provide an In silico framework (i) for modeling the systemic administration of therapeutic agents to solid tumors, their transport properties, and their efficacy in controlling tumor growth and (ii) for the 'rational design' of injectable nano-sized particulate systems (nPSs). The mathematical tools will be multi-scale and multi-physics spanning from the analysis of particulate transport within the vascular compartment (sovracellular level, > 10 um), to the adhesive interactions with the vascular walls and macrophages/Kuppfer cells within the liver sinusoids (cellular level, >1 um and <10 um); to the passive translocation across the vascular endothelium and Gl epithelial layers (sub-cellular level, < 1 um), down to the cellular internalization and intracellular transport (sub-cellular level, 1 um). This core is composed by modules, highly integrated one with the other the other core. Core 1 is co-lead by Drs. Cristini and Decuzzi with the collaboration of Dr. Ferrari and Dr. Macklin. Dr. Cristini (Ph.D. Chemical Engineering, FAAN) is an Associate Professor of Biomedical Engineering and Health Information Sciences at the University of Texas Health Science Center and provides multiscale modeling expertise. Dr. Decuzzi (Ph.D. Mechanical Engineering) is an Associate Professor of Mechanical and Biomedical Engineering at the University of Texas Health Science Center and the Center for Bio/Nanotechnology and Engineering for Medicine at the University of Magna Graecia (In Italy). Dr. Ferrari (Ph.D. Mechanical Engineering) is professor of Professor and Director of the Division of Nanomedicine and Professor of Internal Medicine in the Cardiology Division of The University of Texas Health Science Center, Deputy Chairman of the Department of Biomedical Engineering at the University of Texas. Dr. Macl<lin (Ph.D. Applied Mathematics) is an Assistant Professor of Health Information Sciences at the University of Texas Health Science Center and has researched mathematical modeling of tunnors and their local environment [120-123] and provides expertise in applied mathematics.